The amount of data stored in today's data-centers is rapidly growing, while reliability is becoming more important than ever before.
As a result, storage density is also growing, while disk failure rate is not improving.
This poses major scalability challenges on redundant array of independent disks (RAID) redundancy scheme, due to the increased number of disks, and increased chance for double and triple faults during long disk rebuild times.
RAID 5 calculates a single parity block for multiple data blocks.
The parity block is calculated as the XOR of all data blocks. RAID 5 provides an ability to recover from a single disk failure. The reconstruction of a failed disk requires reading all other disks. There is a relatively high risk for a second disk failure during the reconstruction of the failed disk.
RAID 6 calculates a pair of parity blocks for multiple data blocks. Parity blocks are calculated as XOR and Galois field (GF) multiplication of all data blocks.
RAID 6 provides the ability to recover from up to 2 disk failures. The reconstruction failed disks requires reading all other disks. It was believed to have relatively low risk for a third disk to fail during the reconstruction of two failed disks.
Current solutions for data protection were tailored to a specific RAID level (RDID 5, RAID 6 . . . ).
There is a growing need to provide efficient systems and methods for calculating redundancy in a flexible manner.